He will continue to lead Whitley Bay High, meaning he will be in overall charge of more than 2,300 children.

Dr Kelley was headteacher when a council report branded the school “inadequate” last January.

The school, which has more than 700 pupils aged 13 to 18, was warned the Government would intervene if it did not improve.

The report, carried out by North Tyneside Council criticised pupils’ marks in 2010 exams.

Only 34% of students scored five A* to C grades including English and maths – below the national average.

It said the school needed to improve the skills of leaders and managers as a “matter of urgency”.

But a few months later its GCSE results were the highest in its history.

More than half pupils notched five or more A* to C grades, including English and maths – a rise of almost a fifth.

At the time, Dr Kelley said: “Staff, students and parents have worked together very hard this year. The results have been fantastic.”

Appointed in 1994, he has regularly made headlines for experiments at the school.

Mr Chedburn, his temporary successor, has been headteacher at Whitley Bay since 1993.

Last summer he was named a National Leader of Education after the school achieved 31 outstanding grades in a report by education watchdog Ofsted.

Kat Rowley, whose son goes to Monkseaton High, said: “As a parent, I just find it rather concerning that there’s such a big shake-up and they’ve brought in a headmaster from another school with no proper warning to parents.

“It is very unsettling for parents and pupils, especially when they are sitting their GCSEs.

“The school now does not have a proper headmaster and there was no warning that this was going to happen.

“The correspondence was all very vague.”

The letter, from Anne Welsh, chair of governors, said: “After 17 years as headteacher of Monkseaton High School and CEO of the Innovation Trust, Dr Paul Kelley is now moving on from leading the school.

“Dr Kelley has been instrumental in establishing the new, award-winning building and many new and innovative approaches to enhancing young people’s learning opportunities.”

The letter went on to praise Dr Kelley’s career at the school.

A council spokeswoman said: “Dr Kelley left the school at half term and the governors at Monkseaton High School are currently considering arrangements for succession. In the interim, they have sought the support of an executive headteacher.

“The executive headteacher is Adam Chedburn, a National Leader of Education and headteacher at Whitley Bay High School, a national support school.

“During the interim period, Adam will become executive headteacher at both Monkseaton High School and Whitley Bay High School and he will be supported by a Head of School at each site.”